Question

What are systems of forces?

Answer 1

Hint: We know that a force is a vector quantity which has both direction and magnitude in space and is thus represented by an arrow, where the arrow points towards the direction of the vector force. Then a system of forces is nothing but a collection of forces.

Complete answer:
A force, being a vector can be added to another force by a vector addition. This can also be extended to any number of forces, thus we can say that a collection of forces or the system of forces results in the resultant force.

Additional Information:
Since we know that , we can apply mathematical operations like addition, subtraction, multiplication or division on vectors. We also know that two or more vectors, which are called the system of vectors can be added by vector addition, then we get the resultant vector.
Similarly, a vector can be multiplied by another vector or a scalar like numbers, we can do the former by cross product or vector product and the later by scalar multiplication or dot product.
Since the vectors have direction, there is some angle between the system of vectors, which plays a huge role in the mathematical operations of vectors, which cannot be ignored.

Note:
The direction of the system of forces or any set of vectors, for that matter can be found by the phasor diagram. The addition of vectors is done by the parallelogram law of vector addition. Also the multiplication of vectors by a vector or scalar, gives rise to extra terms, and is hence not like multiplication of two scalars.